Slack history as csv based on content in message

signups.rb

# dependencies:
#   gem install slack-ruby-client
#
# Create a slack app (https://api.slack.com/apps)
#
# Add permissions (Basic Information > Add features and functionality > Permissions)
#   Bot Token scopes: channels:history, channels:read
#
# Get Slack token (Install app > Bot User OAuth Token)
#   - set as environment variable
#
#   SLACK_TOKEN=<your token>
require 'slack-ruby-client'
require 'date'

# Dates of history to request
oldest = Date.new(2021,1,1).to_time.to_i
latest = Date.new(2021,6,1).to_time.to_i

# Slack channel you want history from
CHANNEL = "#pushback"

puts "date,email"
def print_messages(messages)
  messages.each do |msg|
    next unless msg

    # Regex matching the message you want to see
    if msg["text"] =~ /email: (.*)\s+/
     puts "#{DateTime.strptime(msg["ts"].to_s, '%s')},#{$1}"
    end
  end
end

Slack.configure do |config|
  config.token = ENV['SLACK_TOKEN']
end

client = Slack::Web::Client.new
puts client.auth_test
resp = client.conversations_history(latest: latest, oldest: oldest, channel: CHANNEL)
print_messages(resp["messages"])
has_more = resp["has_more"]
while has_more
  resp = client.conversations_history(latest: latest, oldest: oldest, channel: CHANNEL, cursor: resp["response_metadata"]["next_cursor"] )
  raise "Failed" unless resp["ok"]
  print_messages(resp["messages"])
  has_more = resp["has_more"]
end